247(2) Internal troubles
The micro controller can check the following items not
only in the initiation check but also in the circular diagnos-
tic check.
1Trigger transistor of ignition circuit: high-end transistor
can be checked not only in the initiation check but
also in the circular diagnostic check. However, since
the low-end transistor is open when connected in short
circuit to power source, it can only be checked in the
initiation check to avoid explosion.
2The ignition voltage is provided by supercharge
converter.
3The acceleration sensor performs selfcheck in the
initiation check.
4Range of allowed deviation of acceleration sensor in the circular diagnostic check.
5Microcontroller includes AD converter, ROM, RAM, etc.
6Status of safety sensor.NOTICE
The connectors of the squib circuit contain a
shorting bar. When the connector is not
connected, the unexpected deployment is
caused by the short in the circuit arising from
the contact of the positive (+) and negative (-)
terminals or the static electricity. If there is
poor connection for connectors, the symptom
may not be removed even when the shorting
bar is connected.14Ignition c irc uit 4 (passe nger se a t be lt pre tensione r), low re sistanc e
or short c irc uitB1 368
15 Ignition c ircuit 4 (passe nger se a t be lt pre tensione r), groundB1 369
16Ignition c ircuit 4 (passe nger se a t belt pre te nsione r), c onne c t topowe r sourceB1 370
17 High volta ge of powe r sourc e B1 111
18 Low volta ge of power sourc e B1 112
19Warning light trouble -c onne c te d to powe r sourc e or light bulb short
circuitB2 500
20 Warning light trouble -ground or filame nt ope n circ uitB2 500
21 Missing/mistake of the algorithm parameters B1 661
22 Previous crash recordedB1 650
23 Communic a tion trouble B1 407
23 Inte rna l trouble (se e the following ta ble) B1 620
24PADS(
pa ssenge r airba g de a ctiva tion switch)
, c onne c ted topowe r source or open c irc uitB1 527
25PADS(
passenger airbag deactivation switch)
, ground or short
circuitB1 528
26 PADS (passenger airbag deactivation switch), trouble B1 529
27 Cra sh output pin, groundB1 676
28 Cra sh output pin, short c irc uite d to power sourc e B1 677
29PADI (passenger airbag deactivation switch indicator light) error,
c onne c ted to powe r sourc e or light bulb short c irc uitB2 505
30PADI (passenger airbag deactivation switch indicator light) error,
ground or open c irc uitB2 505
31 Se a t be lt pre tensione r se pa ra te ignitionB1 657
32 Se a t be lt pre tensione r se pa ra te ignition for 6 time s B1 658
248An external watchdog can check the operation situation of the microcontroller. The failure of the microcontroller
can trigger the watchdog, which in turn can reset the microcontroller and turn on the warning light.No. List of Trouble s Trouble De sc ription
1 M ic r oc ont r olle r z AD c onve rte r or EEP ROM trouble (in
case of RAM and ROM failure, the
mic r oc ont r olle r w ill r e s e t a nd t he w a r ning
light will light up.) z Activate trouble z
Che ck the circ uit trouble z Activate trouble z Check the circuit trouble z Activate trouble z Chec k the c irc uit trouble z Activate trouble z Chec k the c irc uit trouble z Activate trouble z Check the circuit trouble z Activate trouble z Check the circuit trouble
6 Ignition volta ge z Low
7 Wa tchdog/rese t z Trouble
8 Maximum times of e xplosion of the se a t belt
pretensioner z 6
9 Ene rgy stora ge time (self-support time ) z Short z Ra nge of de via tion z Se nsor not in ste ady mode z Se nsor se lfc hec k trouble
11 Continuous abortion of ignition circ uit che c k z None xec ution of c irc ula r diagnostic test
(Repeated algorithm calculation) z Close for 2 or more tha n 2 sec onds z Sa fe ty se nsor is open c irc uit when
calculating the trouble with algorithm
13 Ignition c urre nt z All the ignition currents are normal
when the current SRS is deployed
14 No c onfirma tion of side SRS ignition z Eve n if the SRS ECU (HAE2.5) ha ve
received for 5 times the ignition information
during the HSIS ignition cyc le, the side SRS
a irba g ignition c a n not be ve rifie d by SRS
ECU (HAE2.5). Seat belt pretensioner ignition circuit (if realized)
5 P asse nger se a t be lt pre tensione r ignition c irc uit
(if realized) 2 P asse nger airba g ignition c ircuit
3 P asse nger airba g ignition c ircuit (if re a lize d)[Ta ble ] Inte rna l troubles pre dic te d by SRS ECU (HAE2.5)
10 Accelerometer
12 Sa fe ty se nsor6 Driver airbag ignition circuit (if realized)
7 P asse nger airba g ignition c ircuit (if re a lize d) 4
249(3) Clear DTCs
When ECU diagnostic tester (Hi-DSTM) receives the "Clear DTCs" command from the serial interface,
the DTCs stored in ECU will be cleared off. But if an internal DTC is recorded or there is one crash
record, the command will not be executed.
5. Trouble display (Warning light ON)
(1) Light bulb check
When working voltage is supplied to SRS ECU (HAE2.5) through battery, SRS ECU (HAE2.5) lights up
the warning light to check the light bulb. In the initiation stage, the light will be on for 6s at the frequency
of 1Hz and then go out. To give notice of the presence of troubles to the driver, the warning light will
remain on after the working voltage is supplied. If the history troubles happened for less than 5 times, the
warning light will be on for 6s after ignition on and then go out. In the initiation stage, the SRS ECU
(HAE2.5) will not check crash and arrest deployment until the circuit of SRS ECU (HAE2.5) goes
stable.
Thus, after ignition on, the display mode of the warning light is one of the following states displayed in the
initiation stage:
STATE 1) The warning light will remain on if there is crash record or the history records of the trouble
are no less than 5 times. Meanwhile, the warning light will remain on if there is explosion trouble.
STATE 2) The history troubles are no less 1 time but less than 5.
("Low battery voltage" shall be excluded from the total number of the troubles.))
STATE 3) Normal (i.e. there is no explosion trouble or history trouble.))
250(2) Trouble indication
1In case of a trouble, the warning light will indicate. If the external trouble is a history trouble, the indication
will be cancelled. When the history trouble happens for no less than 5 times, the indicator light will remain
on even if there is no more trouble. "Low battery voltage" shall not be counted in the total number of
troubles.
2Only a service worker can reset a displayed or history trouble. The internal troubles of a SRS ECU
(HAE2.5) or the "crash record" of a trouble cannot be reset, in which case the SRS ECU (HAE2.5) shall
be replaced.
(3) Microcontroller-independent warning light on
Microcontroller with definitive troubles cannot fulfill its functions, thus cannot control the warning light. In
this case, the warning light will light up through proper circuit regardless of the microcontroller as stated
below:
yMalfunction of the battery supplying power to SRS ECU (HAE2.5): the warning lights are turned
on continuously by means of the drive function of the selfcheck light.
yLoss of internal working voltage: the warning light remains on.
yReset due to trigger failure of the watchdog: the warning light blinks.
yMicrocontroller out of work: the warning light always lights up.
yIncomplete insertion of SRS ECU (HAE2.5) connector: the warning light remains on by means of
a shorting bar.
The diagnostic procedures can well be illustrated as follows:
If it is found that the SRS warning light remains on, follow the undermentioned procedures to check even if
the light goes out eventually. First, a scan meter is used to check the location of the trouble.
Then£¬go on with the checking in accordance with specific methods and procedures for the correspondent
location.
a. If the result indicates that it is an internal trouble or that the SRS is already detonated, replace the
ECU directly.
b. Troubleshooting.
251Section 2 TroubleshootingI. LIST OF TROUBLES1. SRS warning light OFFDIAGNOSTIC PROCEDURESWhen performing the first diagnostic check, it is advised to shake slightly the harness and connector to see if
there is any discontinuous poor contact in circuit. If there is such a problem, make sure that the connections
of the connector, terminals and wire harness are correct and undamaged. Otherwise, follow these procedures:
(1) Check other wire harnesses and instrument cluster indicator lights
1Turn the ignition switch ON.
2Any other light on?
Yes: turn the ignition switch to LOCK, and continue with the next step.
No: check the power supply and ground system (fuse) of the instrument cluster, and continue with step 5.
(2) Check light bulb
CAUTION:
Mishandling of SRS components may release unexpectedly airbag and seat belt pretensioner, probably lead-
ing to a serious accident. Read the service cautions before handling a SRS component.
1Turn the ignition switch to LOCK.
2Disconnect the negative (-) terminal cable from the battery and wait for at least 60s.
3Remove the instrument cluster.
4Measure and see if the two pins of the SRS warning light is triggered.
Yes: continue with next step.
No: replace the bulb of the warning light.
Trouble Che c king Status P ossible Ca use
·Loss of voltage (fuse c irc uit bre a k)
·Instrument cluster trouble
·Trouble of wire harness between instrument
cluster and ECU SRS warning light OFF SRS wa rning c ircuit trouble1 SRS warning light is OFF SRS wa rning c irc uit trouble. No. Trouble shooting Ite ms De sc ription
2 SRS warning light re mains on SRS wa rning circ uit trouble or exte rna l trouble.
252(3)Check the connection between ECU and instrument cluster
1Turn the ignition switch to LOCK.
2Disconnect the negative (-) terminal cable from the battery.
3Disconnect the connector of instrument cluster.
4Check if the related circuits of the warning light are connected or not.
Yes: continue with next step.
No: replace the wire harness, and then continue with step 5.
2. SRS warning light remains on.DIAGNOSTIC PROCEDURESTo begin the check, first use special diagnostic instruments and ECU to perform communication diagnosis
and find out the causes of the trouble. If the communication fails, continue with the following procedures:
(1) Check battery
1Check battery voltage.
2Is voltage higher than 9V?
Yes: continue with next step.
No: Insufficient battery supply. Check the charging/discharging system, and then continue with step (5).
(2) Check the continuity of the wire harness between ECU and instrument cluster
1Turn the ignition switch to LOCK.
2Disconnect negative (-) terminal cable from the battery.
3Open the guard plate of the central passage.
4Disconnect the connector of the instrument cluster.
5Connect the negative (-) terminal cable of the battery.
6Turn the ignition switch ON.
7Check whether the voltage of the connector terminal of the instrument is 12V (power supply and instrument
connecting wire).Trouble Che cking Sta tus P ossible Cause z Insufficient battery supply z ECU internal trouble z SRS wa rning light trouble of instrument c luste r z Improper connection of ECU connector z P oor c ontac t of instrume nt c luste r c onne c tor z Ope n circ uit or poor c onta c t of ECU power supply fuse z P oor c onne c tion of ECU connec tor te rmina l z P oor conta ct of the wire ha rne ss be twe en ECU
connec tor te rmina l a nd ground z Drive r or pa ssenge r side circ uit trouble of SRS SRS wa rning light
remains onSRS warning light
remains on
253Yes: continue with next step.
No: check the circuit, repair it and continue with step (5).
8Turn the ignition switch to LOCK.
9Check the continuity of the terminal of instrument connector and that of diagnostic interface (check the
two ends of K line).
Yes: continue with next step.
No: repair or replace the wire harness. Continue with step (5).
VMake sure to disconnect the negative terminal cable from the battery and wait for at least 60s.Disconnect
the ECU connector. 11Disconnect the connectors of the instrument cluster 12 Are the connector terminals 5, 7 and 9 and those of instrument cluster continuity?
Yes: continue with next step.
No: replace the wire harness, and then continue with step (5). 13Remove ECU and see whether the terminals are in good condition and whether the shorting bar is
broken.
Yes: replace the ECU.
No: reconnect the ECU connector, and then continue with next step.
(3) Make sure of the nonrecurrence of the trouble after repair
1Turn the ignition switch to LOCK.
2Disconnect the negative (-) terminal cable from the battery and wait for at least 60s.
3Connect all the ECU connectors.
4Connect the connector of driver airbag assembly.
5Connect the connector of passenger airbag assembly.
6Connect the connectors of driver and passenger seat belt pretensioners (vehicle with pretensioner).
7Connect clock spring connector.
8Connect the negative (-) terminal cable of the battery.
9Turn the ignition switch to ON.
VIs the SRS warning light working normal?
Yes: the trouble is eliminated. Explain the repair procedures to the Customer.
No: recheck symptoms of the trouble. Repeat these procedures from the first step if the trouble reoccurs.
261IV. WARNING MARKSWhen using or maintaining an airbag, the warnings shall be indicated. When maintaining, proceed in accor-
dance with the description of mark. In addition, if the mark is damaged or stained, it shall be replaced.
1. Driver airbag assembly, see Fig. 1.
2. Clock spring, see Fig. 2.
3. ECU, see Fig. 3.
4. Sun Visor, see Fig. 4.
5. Steering wheel, Fig. 5.Warning MarkFigure 1Warning
MarkFigure 2Warning Mark
Figure 3Warning Mark Warning MarkFigure 4 Sun VisorFigure 5